SIEGEL: Here's a thought for those of you listening to us now on your iPod or your smartphone or an Internet radio. Cost, distance and a lack of infrastructure mean that most people on Earth, more than 4.5 billion people, are not connected to the Internet. And this week, people at Google X, the company's research lab, said that they hope to address that problem with balloons, a network of high-altitude helium balloons offering Internet access.

NPR's Steve Henn is joining us now. Hi, Steve.

STEVE HENN, BYLINE: Hi.

SIEGEL: Google is famous for April Fools' jokes. Is this just one that happens to happen in June?

(LAUGHTER)

HENN: No. No, they're actually serious about this, although they did call the project Loon, which is short for balloon, but I think also sort of a head nod to the fact that it sounds a bit odd.

SIEGEL: How many balloons? How high up? How long would they stay there?

HENN: Well, it's very early days. So they just finished a test of this in New Zealand. And the balloons will fly at about 20 kilometers, which is the stratosphere, and that's about twice as high as an airplane flies. And the first test was with a couple dozen balloons. But ultimately, for the system to work, I mean, you'd need quite a few balloons. The balloons only cover an area of about 40 square kilometers right now on the ground.

SIEGEL: So we're talking about hundreds or thousands of balloons, each of which could put in about how many months' service?

HENN: They hope that each balloon could stay afloat for 100 days or more right now.

SIEGEL: So Google is thinking of going into the balloon launching business.

(LAUGHTER)

HENN: Yes, apparently so. Right?

SIEGEL: How big are the balloons?

HENN: The balloons are about 15 meters across. That's roughly 50 feet and about 12 meters high. They each have a solar panel floating below them, which powers the radio connectivity that sends a signal to the ground and also to other balloons. So these balloons connect to each other and then back to an ISP on the ground.

SIEGEL: Connect, by signal you mean. They're not physically connected to each other.

HENN: No.

SIEGEL: And they're obviously not tethered up there or planes would constantly be dragging balloons with them.

(LAUGHTER)

SIEGEL: What will control where they are, their locations, for people who would use them for Internet connectivity?

HENN: Well, ultimately, they're controlled by changing their altitude in the sky. So there - NOAA has a map of stratospheric winds. And these winds blow in slightly different directions and at different speeds. So by adjusting the balloon's position in the air column, Google can predict where an individual balloon will go and try to make sure that it stays within range of its network and is covering the area on the ground that they want to serve with an Internet connection.

SIEGEL: That standard that they try to keep it within range of its network suggests this may not be the most reliable Internet signal you'll get if you're using this system.

HENN: Right. And in the test in New Zealand this week, they described it as somewhat less than constant connectivity.

(LAUGHTER)

SIEGEL: Less than constant, not a great ad campaign.

HENN: Well, it's early.

(LAUGHTER)

SIEGEL: Is the assumption here that this is cheaper than just launching satellites and having more connectivity down there?

HENN: Yeah, that's the idea, that it would actually be cheaper to launch a network of balloons that was dense enough to be in constant contact with each other, rotating around the entire planet, than it would be to launch a satellite. And right now, satellite Internet connectivity is tremendously expensive and slow.

SIEGEL: So an idea or it's a go?

HENN: It's an idea, but they're taking it seriously. They've made it public. And I think we'll be talking about this in the future.